The invention herein described was made under contract with the Department of the Army of the United States of America.
The present invention relates to belt-fed, gas-operated, air-cooled, automatic firearms having mechanisms for transferring link-connected rounds from an ammunition magazine to a feed position in an automatic firearm and to sear mechanisms therefor.
In automatic firearms capable of firing at the rates of about 400 to 500 rounds of ammunition per minute, it is essential to have a reliable transfer feed mechanism capable of supplying ammunition and removing a round of ammunition from the ammunition supply carrier such as a link belt and accurately transferring the round to a feed position in front of the bolt carrier without causing a stoppage of the automatic firearm. The rigorous conditions of a battlefield environment demand a high level of performance where success depends on the reliable performance of the automatic firearm.
To prevent the bolt carrier from being prematurely driven away from the barrel when the bolt carrying the round advances to firing position, it is desirable to utilize an anti-bounce sear to lock the bolt carrier in position shortly prior to and during the firing of the round of ammunition. Without an anti-bounce sear, it is possible, as in firearms within the current state of the art to fire a round of ammunition without having the bolt fully locked in the barrel thereby causing a stoppage in the firearm and possible injury to the user.
Prior art automatic firearm transfer mechanisms have been complex, difficult to maintain and subject to numerous stoppages.
A primary object of this invention is to provide an improved ammunition magazine assembly, feed mechanism and anti-bounce sear for automatic firearms which operate more smoothly and efficiently than has occurred in prior art automatic firearms.
Another object of this invention is to provide such an ammunition magazine, a feed mechanism and an anti-bounce sear for automatic firearms which decrease the number of stoppages associated with the feed mechanism to increase the effectiveness of the firearm in a battlefield environment.
An additional object of the present invention is to improve the maintainability of automatic firearms which must be used under adverse field conditions including mud, rain, ice and snow.
A further object of the present invention is to provide an ammunition magazine capable of storing belted rounds of ammunition which may be withdrawn easily without stoppages.
A still further object of the present invention is to provide an ammunition magazine which protects the rounds of ammunition from the environment while providing a visible means for determining the quantity of ammunition remaining in the ammunition magazine.
A still further object of the present invention is to reduce the complexity of feed mechanisms in automatic firearms thereby decreasing cost and the quantities of spare parts which must be maintained.
Another object of the present invention is to provide an anti-bounce sear which prevents the ammunition round from being fired until the bolt carrying the round is locked in a firing position adjacent the rear of the barrel.
An additional object of the present invention is to provide an anti-bounce sear which reduces the possibility of injury to the user of the firearm by preventing firing of the ammunition round until the bolt carrier is locked in the firing position.
These and other objects of the present invention will become apparent from the following description, taken in conjunction with the accompanying drawings.